Identify that film

<p>I am scanning my father's collection of slides and have come across a rather odd film type that is creating some confusion for me. I can best describe this film by the way it behaves when being scanned - hence my posting here for some information. I am scanning using a Coolscan 5000 with NikonScan software.</p>

<p>The film is about 50 years old. It behaves approximately half way between Kodachrome and other slide film in that ICE creates artifacts - but not as many as with Kodachrome. Scanning with the settings of Kodachrome and ICE I get good scans without any artifacts (something that can't be said of actual Kodachrome on the 5000); scanning with normal ICE creates artifacts along light/dark boundaries. For this and the reasons mentioned below I don't think it actually is Kodachrome, but it certainly isn't like the Agfa slides which form the bulk of the non-Kodachrome collection.<br>

Looking at the film it is very thick and dense on the emulsion side (probably accounting for the ICE problems) and has some patterning like on Kodachrome, but without the silvery etched look of Kodachrome. The colours are quite saturated. Furthermore, all of the slides I've seen so far are suffering from a red shift in a way that the Kodachromes aren't. In some cases I've thought that they were heat affected from spending too long in a projector, but they are the only frames looking like that in the slide collection so that doesn't seem likely. On a few of the slides that are in reclosable plastic mounts I've opened them up and haven't seen any markings on the film margins to identify it other than the fact that frame numbers are in half-frame increments (that is, numbers running up to 60 or 70 with 2 per frame) rather than full frame numbering as is used these days. Any suggestions for what this is?</p>

<p>(I've also come across some B&W Gavaert slides that look really sweet. Very fine grained and with a slight sepia tint. These are less of a mystery, but look really good compared with many of the B&W negatives I've been scanning from this era.)</p>

<p>I would suggest you to scan one slide with frame numbered sides. Although I definetly do not know nothing about diapositives 50 years old.</p>

<p>Finally came across a frame with identification on it: Perutz Color C18</p>

<p>Anyone know anything about this film?</p>

<p>Search photo.net and Google "perutz film." A fair amount of information will be found.</p>

<p>I used Perutz for some slide pictures back when (early 1960s sometime) they tried marketing in the USA. The slide film was very much like Ansco with a fairly pronounced tint to the brown color spectrum when fresh as I recall. The slides preserve very poorly, although they can be repaired to some extent in post-processing in PS. I'd bet that the color-negative dye stability isn't much better.</p>

<p>Based on my sample of 40-50 year old slides and colour negatives I would say the absolute worst for stability is Kodacolor II and Agfa CN S colour negatives. Everything else has been basically recoverable in post. The CN S had gone blotchy which is pretty much impossible to deal with with my skills. By comparison, the Perutz is wonderful.<br>

I didn't find much information about the technical qualities of the slide film using Google. A few other people asking what this film is and a nice history of the company.</p>

<p>I would agree on the Agfa. However, I am curious about the Kodacolor. I used only a little of it, but what I did was processed by Kodak and is still fairly close to original after 40-50 years. Was your Kodacolor processed by Kodak?</p>

<p>I have certainly noticed that non-Kodak processing on Ektachrome makes a huge difference in archival preservation -- the old Ektachrome I have that was processed by Kodak is still good, but film done by the big West Coast processors has faded very badly.</p>

<p>I have no idea about processing. It was done in Australia and Kenya when I was knee-high to a grasshopper. The older Kodacolor-X is pretty good (if a little un-natural). But the Kodacolor-II from 1974-1978 that I've done so far is pretty bad. It might be getting marginally better the closer to the present I get, but it is all very green out of the box and requires significant adjustment to get close to natural; I always end up with clipped highlights for at least two of RGB when it is looking natural - presumably from dye fading. By way of contrast, mixed in with the Kodacolor-II from the mid-70s is the occasional "Pacific Colour Film" that is very good. If the processing was done in the same places this still points to there being something sub-standard about the Kodacolor-II.</p>